HTML to PDF in Ruby

Overview

This document describes how to convert web pages and HTML documents to PDF in Ruby using the Pdfcrowd API. The API is easy to use and the integration takes only a couple of lines of code.

Getting Started

Enter a web page or upload an HTML file to get a PDF preview and auto-generated integration code that you can copy and paste to your application.

Or choose from the examples below and adapt the code to your needs.

You can also interactively explore the API in our API Playground.

Installation

Install the client library from rubygems.org

gem install pdfcrowd

Or learn about other installation options.

Authentication

Authentication is needed in order to use the Pdfcrowd API. The credentials used for accessing the API are your Pdfcrowd username and the API key.

You can try out the API without registration using the following demo credentials:

Username: demo
API key: ce544b6ea52a5621fb9d55f8b542d14d

Or you can start a free trial or purchase the API license to get your personal API credentials.

Examples

Convert a web page to a PDF file

require "pdfcrowd"

begin
    # create the API client instance
    client = Pdfcrowd::HtmlToPdfClient.new("demo", "ce544b6ea52a5621fb9d55f8b542d14d")

    # run the conversion and write the result to a file
    client.convertUrlToFile("http://www.example.com", "example.pdf")
rescue Pdfcrowd::Error => why
    # report the error
    STDERR.puts "Pdfcrowd Error: #{why}"

    # rethrow or handle the exception
    raise
end

Convert a web page to in-memory PDF

require "pdfcrowd"

begin
    # create the API client instance
    client = Pdfcrowd::HtmlToPdfClient.new("demo", "ce544b6ea52a5621fb9d55f8b542d14d")

    # run the conversion and store the result into the "pdf" variable
    pdf = client.convertUrl("http://www.example.com")

    # at this point the "pdf" variable contains PDF raw data and
    # can be sent in an HTTP response, saved to a file, etc.
rescue Pdfcrowd::Error => why
    # report the error
    STDERR.puts "Pdfcrowd Error: #{why}"

    # rethrow or handle the exception
    raise
end

Convert a web page and write the resulting PDF to an output stream

require "pdfcrowd"

begin
    # create the API client instance
    client = Pdfcrowd::HtmlToPdfClient.new("demo", "ce544b6ea52a5621fb9d55f8b542d14d")

    # create an output stream for the conversion result
    output_stream = open("example.pdf", "wb")

    # run the conversion and write the result into the output stream
    client.convertUrlToStream("http://www.example.com", output_stream)

    # close the output stream
    output_stream.close()
rescue Pdfcrowd::Error => why
    # report the error
    STDERR.puts "Pdfcrowd Error: #{why}"

    # rethrow or handle the exception
    raise
end

Convert a local HTML file to a PDF file

require "pdfcrowd"

begin
    # create the API client instance
    client = Pdfcrowd::HtmlToPdfClient.new("demo", "ce544b6ea52a5621fb9d55f8b542d14d")

    # run the conversion and write the result to a file
    client.convertFileToFile("/path/to/MyLayout.html", "MyLayout.pdf")
rescue Pdfcrowd::Error => why
    # report the error
    STDERR.puts "Pdfcrowd Error: #{why}"

    # rethrow or handle the exception
    raise
end

Convert a local HTML file to in-memory PDF

require "pdfcrowd"

begin
    # create the API client instance
    client = Pdfcrowd::HtmlToPdfClient.new("demo", "ce544b6ea52a5621fb9d55f8b542d14d")

    # run the conversion and store the result into the "pdf" variable
    pdf = client.convertFile("/path/to/MyLayout.html")

    # at this point the "pdf" variable contains PDF raw data and
    # can be sent in an HTTP response, saved to a file, etc.
rescue Pdfcrowd::Error => why
    # report the error
    STDERR.puts "Pdfcrowd Error: #{why}"

    # rethrow or handle the exception
    raise
end

Convert a local HTML file and write the resulting PDF to an output stream

require "pdfcrowd"

begin
    # create the API client instance
    client = Pdfcrowd::HtmlToPdfClient.new("demo", "ce544b6ea52a5621fb9d55f8b542d14d")

    # create an output stream for the conversion result
    output_stream = open("MyLayout.pdf", "wb")

    # run the conversion and write the result into the output stream
    client.convertFileToStream("/path/to/MyLayout.html", output_stream)

    # close the output stream
    output_stream.close()
rescue Pdfcrowd::Error => why
    # report the error
    STDERR.puts "Pdfcrowd Error: #{why}"

    # rethrow or handle the exception
    raise
end

Convert a string containing HTML to a PDF file

require "pdfcrowd"

begin
    # create the API client instance
    client = Pdfcrowd::HtmlToPdfClient.new("demo", "ce544b6ea52a5621fb9d55f8b542d14d")

    # run the conversion and write the result to a file
    client.convertStringToFile("<html><body><h1>Hello World!</h1></body></html>", "HelloWorld.pdf")
rescue Pdfcrowd::Error => why
    # report the error
    STDERR.puts "Pdfcrowd Error: #{why}"

    # rethrow or handle the exception
    raise
end

Convert a string containing HTML to in-memory PDF

require "pdfcrowd"

begin
    # create the API client instance
    client = Pdfcrowd::HtmlToPdfClient.new("demo", "ce544b6ea52a5621fb9d55f8b542d14d")

    # run the conversion and store the result into the "pdf" variable
    pdf = client.convertString("<html><body><h1>Hello World!</h1></body></html>")

    # at this point the "pdf" variable contains PDF raw data and
    # can be sent in an HTTP response, saved to a file, etc.
rescue Pdfcrowd::Error => why
    # report the error
    STDERR.puts "Pdfcrowd Error: #{why}"

    # rethrow or handle the exception
    raise
end

Convert a string containing HTML and write the resulting PDF to an output stream

require "pdfcrowd"

begin
    # create the API client instance
    client = Pdfcrowd::HtmlToPdfClient.new("demo", "ce544b6ea52a5621fb9d55f8b542d14d")

    # create an output stream for the conversion result
    output_stream = open("HelloWorld.pdf", "wb")

    # run the conversion and write the result into the output stream
    client.convertStringToStream("<html><body><h1>Hello World!</h1></body></html>", output_stream)

    # close the output stream
    output_stream.close()
rescue Pdfcrowd::Error => why
    # report the error
    STDERR.puts "Pdfcrowd Error: #{why}"

    # rethrow or handle the exception
    raise
end

Get info about the current conversion

require "pdfcrowd"

begin
    # create the API client instance
    client = Pdfcrowd::HtmlToPdfClient.new("demo", "ce544b6ea52a5621fb9d55f8b542d14d")

    # configure the conversion
    client.setDebugLog(true)

    # run the conversion and write the result to a file
    client.convertFileToFile("/path/to/MyLayout.html", "MyLayout.pdf")
    
    # print URL to the debug log
    puts "Debug log url: #{client.getDebugLogUrl()}"
    
    # print the number of available conversion credits in your account
    puts "Remaining credit count: #{client.getRemainingCreditCount()}"
    
    # print the number of credits consumed by the conversion
    puts "Consumed credit count: #{client.getConsumedCreditCount()}"
    
    # print the unique ID of the conversion
    puts "Job id: #{client.getJobId()}"
    
    # print the total number of pages in the output document
    puts "Page count: #{client.getPageCount()}"
    
    # print the size of the output in bytes
    puts "Output size: #{client.getOutputSize()}"
rescue Pdfcrowd::Error => why
    # report the error
    STDERR.puts "Pdfcrowd Error: #{why}"

    # rethrow or handle the exception
    raise
end

Advanced Examples

Customize the page size and the orientation

require "pdfcrowd"

begin
    # create the API client instance
    client = Pdfcrowd::HtmlToPdfClient.new("demo", "ce544b6ea52a5621fb9d55f8b542d14d")

    # configure the conversion
    client.setPageSize("Letter")
    client.setOrientation("landscape")
    client.setNoMargins(true)

    # run the conversion and write the result to a file
    client.convertUrlToFile("http://www.example.com", "letter_landscape.pdf")
rescue Pdfcrowd::Error => why
    # report the error
    STDERR.puts "Pdfcrowd Error: #{why}"

    # rethrow or handle the exception
    raise
end

Put the source URL in the header and the page number in the footer

require "pdfcrowd"

begin
    # create the API client instance
    client = Pdfcrowd::HtmlToPdfClient.new("demo", "ce544b6ea52a5621fb9d55f8b542d14d")

    # configure the conversion
    client.setHeaderHeight("15mm")
    client.setFooterHeight("10mm")
    client.setHeaderHtml("<a class='pdfcrowd-source-url' data-pdfcrowd-placement='href-and-content'></a>")
    client.setFooterHtml("<center><span class='pdfcrowd-page-number'></span></center>")
    client.setMarginTop("0")
    client.setMarginBottom("0")

    # run the conversion and write the result to a file
    client.convertUrlToFile("http://www.example.com", "header_footer.pdf")
rescue Pdfcrowd::Error => why
    # report the error
    STDERR.puts "Pdfcrowd Error: #{why}"

    # rethrow or handle the exception
    raise
end

Zoom the HTML document

require "pdfcrowd"

begin
    # create the API client instance
    client = Pdfcrowd::HtmlToPdfClient.new("demo", "ce544b6ea52a5621fb9d55f8b542d14d")

    # configure the conversion
    client.setScaleFactor(300)

    # run the conversion and write the result to a file
    client.convertUrlToFile("http://www.example.com", "zoom_300.pdf")
rescue Pdfcrowd::Error => why
    # report the error
    STDERR.puts "Pdfcrowd Error: #{why}"

    # rethrow or handle the exception
    raise
end

Set PDF metadata

require "pdfcrowd"

begin
    # create the API client instance
    client = Pdfcrowd::HtmlToPdfClient.new("demo", "ce544b6ea52a5621fb9d55f8b542d14d")

    # configure the conversion
    client.setAuthor("Pdfcrowd")
    client.setTitle("Hello World")
    client.setSubject("Demo")
    client.setKeywords("Pdfcrowd,demo")

    # run the conversion and write the result to a file
    client.convertUrlToFile("http://www.example.com", "with_metadata.pdf")
rescue Pdfcrowd::Error => why
    # report the error
    STDERR.puts "Pdfcrowd Error: #{why}"

    # rethrow or handle the exception
    raise
end

Create a Powerpoint like presentation from an HTML document

require "pdfcrowd"

begin
    # create the API client instance
    client = Pdfcrowd::HtmlToPdfClient.new("demo", "ce544b6ea52a5621fb9d55f8b542d14d")

    # configure the conversion
    client.setPageLayout("single-page")
    client.setPageMode("full-screen")
    client.setInitialZoomType("fit-page")
    client.setOrientation("landscape")
    client.setNoMargins(true)

    # run the conversion and write the result to a file
    client.convertUrlToFile("https://pdfcrowd.com/doc/api/", "slide_show.pdf")
rescue Pdfcrowd::Error => why
    # report the error
    STDERR.puts "Pdfcrowd Error: #{why}"

    # rethrow or handle the exception
    raise
end

Convert an HTML document section

require "pdfcrowd"

begin
    # create the API client instance
    client = Pdfcrowd::HtmlToPdfClient.new("demo", "ce544b6ea52a5621fb9d55f8b542d14d")

    # configure the conversion
    client.setElementToConvert("#main")

    # run the conversion and write the result to a file
    client.convertUrlToFile("https://pdfcrowd.com/doc/api/", "html_part.pdf")
rescue Pdfcrowd::Error => why
    # report the error
    STDERR.puts "Pdfcrowd Error: #{why}"

    # rethrow or handle the exception
    raise
end

Inject an HTML code

require "pdfcrowd"

begin
    # create the API client instance
    client = Pdfcrowd::HtmlToPdfClient.new("demo", "ce544b6ea52a5621fb9d55f8b542d14d")

    # configure the conversion
    client.setCustomJavascript("el=document.createElement('h2'); el.textContent='Hello from Pdfcrowd API'; el.style.color='red'; el_before=document.getElementsByTagName('h1')[0]; el_before.parentNode.insertBefore(el, el_before.nextSibling)")

    # run the conversion and write the result to a file
    client.convertUrlToFile("http://www.example.com", "html_inject.pdf")
rescue Pdfcrowd::Error => why
    # report the error
    STDERR.puts "Pdfcrowd Error: #{why}"

    # rethrow or handle the exception
    raise
end

Convert a responsive web page as it appears on a large device

require "pdfcrowd"

begin
    # create the API client instance
    client = Pdfcrowd::HtmlToPdfClient.new("demo", "ce544b6ea52a5621fb9d55f8b542d14d")

    # configure the conversion
    client.setViewportWidth(992)
    client.setRenderingMode("viewport")
    client.setSmartScalingMode("viewport-fit")
    client.setNoMargins(true)

    # run the conversion and write the result to a file
    client.convertUrlToFile("https://getbootstrap.com/", "bootstrap.pdf")
rescue Pdfcrowd::Error => why
    # report the error
    STDERR.puts "Pdfcrowd Error: #{why}"

    # rethrow or handle the exception
    raise
end

Create an in-memory archive (ZIP) and convert it

require "pdfcrowd"
require "zip"

begin
    # create the API client instance
    client = Pdfcrowd::HtmlToPdfClient.new("demo", "ce544b6ea52a5621fb9d55f8b542d14d")

    # create ZIP archive
    in_stream = Zip::OutputStream.write_buffer do |zip_io|
        # add HTML content to the archive
        zip_io.put_next_entry("index.html")
        zip_io.write "<html>
            <head>
                <style>
                 @font-face
                 {
                     font-family: 'OpenSans';
                     src: url(fonts/OpenSans.ttf) format('truetype');
                 }
        
                 h1
                 {
                     font-family: OpenSans;
                 }
                </style>
            </head>
            <body>
                <h1>Hello World</h1>
                <img src='images/logo.png'>
            </body>
        </html>"

        # add required local files to the archive
        zip_io.put_next_entry("fonts/OpenSans.ttf")
        File.open("/your-path-to/fonts/OpenSans.ttf", "rb") do |in_file|
            zip_io.write in_file.read
        end
        zip_io.put_next_entry("images/logo.png")
        File.open("/your-path-to/images/logo.png", "rb") do |in_file|
            zip_io.write in_file.read
        end
    end

    in_stream.rewind

    # create an output stream for the conversion result
    output_stream = open("HelloFromZip.pdf", "wb")

    # run the conversion and write the result into the output stream
    client.convertStreamToStream(in_stream, output_stream)

    # close the output stream
    output_stream.close()
rescue Pdfcrowd::Error => why
    # report the error
    STDERR.puts "Pdfcrowd Error: #{why}"

    # rethrow or handle the exception
    raise
end

Renderer debugging - highlight HTML elements

require "pdfcrowd"

begin
    # create the API client instance
    client = Pdfcrowd::HtmlToPdfClient.new("demo", "ce544b6ea52a5621fb9d55f8b542d14d")

    # configure the conversion
    client.setCustomJavascript("libPdfcrowd.highlightHtmlElements({backgroundColor: 'rgba(255, 191, 0, 0.1)', borderColor:null})")

    # run the conversion and write the result to a file
    client.convertUrlToFile("http://www.example.com", "highlight_background.pdf")
rescue Pdfcrowd::Error => why
    # report the error
    STDERR.puts "Pdfcrowd Error: #{why}"

    # rethrow or handle the exception
    raise
end

Renderer debugging - borders with spacing around HTML elements

require "pdfcrowd"

begin
    # create the API client instance
    client = Pdfcrowd::HtmlToPdfClient.new("demo", "ce544b6ea52a5621fb9d55f8b542d14d")

    # configure the conversion
    client.setCustomJavascript("libPdfcrowd.highlightHtmlElements({borderColor: 'orange', backgroundColor: null, padding: '4px', margin: '4px'})")

    # run the conversion and write the result to a file
    client.convertUrlToFile("http://www.example.com", "highlight_borders.pdf")
rescue Pdfcrowd::Error => why
    # report the error
    STDERR.puts "Pdfcrowd Error: #{why}"

    # rethrow or handle the exception
    raise
end

Integration Examples

The API can be easily integrated into your environment. You can have our interactive API Playground autogenerate the integration code for you:

You can also check out a complete example in our pdfcrowd-examples Github repository:

HTML to PDF in Ruby on Rails

Common Customizations

The API lets you convert a web page, a local HTML file, or a string containing HTML. The result of the conversion can be stored to a local file, to a stream object or to a variable. See the conversion input section for more details.

The best way to start with the API is to choose one of the examples and once you get it working, you can further customize the code. You can find the most common customizations in the table below.

Page size	Change the page size with setPageSize or setPageDimensions . Pass -1 to setPageHeight to get a single page PDF containing the whole document.
Page orientation	Change the page orientation to landscape with setOrientation.
Page margins	Adjust the page margins with setPageMargins.
Headers and footers	Add headers and footers with setHeaderHtml and setFooterHtml. Set the height with setFooterHeight and setHeaderHeight.
Zoom	Scale the HTML contents with setScaleFactor.
Hide or remove elements	You can use the following classes in your HTML code to hide or remove elements from the output: `pdfcrowd-remove` - sets `display:none!important` on the element `pdfcrowd-hide` - sets `visibility:hidden!important` on the element
Use @media print	You can switch to the print version of the page (if it exists) with setUsePrintMedia.
Force page break	You can force a page break with `<div style="page-break-before:always"></div>`
Avoid page break	You can avoid a page break inside an element with the following CSS `th, td, img { page-break-inside:avoid }`
Run custom JavaScript	You can use setOnLoadJavascript or setCustomJavascript to alter the HTML contents with a custom JavaScript. In addition to the standard browser APIs, the custom JavaScript code can use helper functions from our JavaScript library .
Custom CSS styling	You can alter CSS styling used during conversion with a custom JavaScript or using the `pdfcrowd-body` CSS class, which is automatically set on the HTML <body> element. You can, for example, set the H1 height to 48px by adding the following line to your CSS: `.pdfcrowd-body h1 { font-size: 48px; }`

Template Rendering

The API enables rendering of HTML templates. The template syntax is based on the Jinja template rendering engine.

The most common constructs are:

Data rendering: Invoice: {{ invoice.number }}
For loop: {% for invoice in invoices %} ... {% endfor %}
If statement: {% if invoice.total > 100 %} ... {% endif %}
Data filter: {{ invoice.to.first_name|capitalize }}

The supported input data formats are JSON, XML, CSV and YAML. The data can be uploaded from a file or from a string variable.

Supported template filters: capitalize, center, default, escape, first, forceescape, format, indent, join, last, length, list, lower, replace, reverse, safe, slice, sort, string, striptags, title, trim, truncate, unique, upper, wordcount, wordwrap.

Template Rendering Examples

Create PDF from JSON data

require "pdfcrowd"

begin
    # create the API client instance
    client = Pdfcrowd::HtmlToPdfClient.new("{{ user_name }}", "{{ api_key }}")

    # configure the conversion
    client.setDataString('{
            "name": "World",
            "product": "Pdfcrowd API"
        }')

    # run the conversion and write the result to a file
    client.convertStringToFile("Hello {{ name }} from {{ product }}", "output.pdf")
rescue Pdfcrowd::Error => why
    # report the error
    STDERR.puts "Pdfcrowd Error: #{why}"

    # rethrow or handle the exception
    raise
end

Create PDF from XML data

require "pdfcrowd"

begin
    # create the API client instance
    client = Pdfcrowd::HtmlToPdfClient.new("{{ user_name }}", "{{ api_key }}")

    # configure the conversion
    client.setDataString('<?xml version="1.0" encoding="UTF-8"?>
        <data>
          <name>World</name>
          <product>Pdfcrowd API</product>
        </data>')

    # run the conversion and write the result to a file
    client.convertStringToFile("Hello {{ data.name }} from {{ data.product }}", "output.pdf")
rescue Pdfcrowd::Error => why
    # report the error
    STDERR.puts "Pdfcrowd Error: #{why}"

    # rethrow or handle the exception
    raise
end

Create PDF from YAML data

require "pdfcrowd"

begin
    # create the API client instance
    client = Pdfcrowd::HtmlToPdfClient.new("{{ user_name }}", "{{ api_key }}")

    # configure the conversion
    client.setDataString("name: World
product: Pdfcrowd API")

    # run the conversion and write the result to a file
    client.convertStringToFile("Hello {{ name }} from {{ product }}", "output.pdf")
rescue Pdfcrowd::Error => why
    # report the error
    STDERR.puts "Pdfcrowd Error: #{why}"

    # rethrow or handle the exception
    raise
end

Create PDF from CSV data

require "pdfcrowd"

begin
    # create the API client instance
    client = Pdfcrowd::HtmlToPdfClient.new("{{ user_name }}", "{{ api_key }}")

    # configure the conversion
    client.setDataString("name,product
World,Pdfcrowd API")

    # run the conversion and write the result to a file
    client.convertStringToFile("Hello {{ name }} from {{ product }}", "output.pdf")
rescue Pdfcrowd::Error => why
    # report the error
    STDERR.puts "Pdfcrowd Error: #{why}"

    # rethrow or handle the exception
    raise
end

Error Handling

begin 
    # call the API 
rescue Pdfcrowd::Error => why 
    # print error
    STDERR.puts "Pdfcrowd Error: #{why}"

    # print just error code
    STDERR.puts "Pdfcrowd Error Code: #{why.getCode()}"

    # print just error message
    STDERR.puts "Pdfcrowd Error Message: #{why.getMessage()}"

    # or handle the error in your way
end

Troubleshooting

Check API Status Codes in case of the error code is returned.
You can use setDebugLog and getDebugLogUrl to get detailed info about the conversion, such as conversion errors, time, console output.
You can use our JavaScript library to resolve rendering problems, such as missing content or blank pages.
Just use setCustomJavascript with libPdfcrowd.highlightHtmlElements method call to visualize all HTML elements. See the backgrounds example , borders example and helper JavaScript library documentation.
Take a look at the FAQ section.

API Method Reference

Refer for details to the API Method Reference.